1. Technical Field
This invention relates to pen-based computing items. Specifically, this invention relates to a method and apparatus for erasing information from the screen of a pen-based computer.
2. Description of the Related Art
As the popularity of pen-based computer systems has grown, so has the need for quick and efficient methods to manipulate images on these computers"" displays. One specific type of function that can greatly enhance the functionality of a pen-based computer system is the ability to quickly and easily remove information from the display. A well-designed erase function enhances functionality by making it easy to edit and delete text and graphics from the display.
The prior art has addressed the general problem of erasing unwanted information from a computer display in a number of ways. Some prior art computer systems allow a user to select an object (e.g., an icon, a paragraph, etc.) and then command the computer system to delete that object. For example, in a word processing program, a user may be able to select an entire paragraph of text and then command the computer system to delete that text. This approach is not effective for pen-based computer systems because information is often not stored in discreet, organized sections.
Another prior art solution allows the user to convert the cursor into an electronic eraser. Information from the display can then be deleted by moving the cursor over it. However, this type of erase function does not make efficient use of the movements of the cursor, and it can be difficult to completely erase all of the information in a given area.
Yet a final prior art solution allows a user to encircle an area of information on the computer display and then mark that area for deletion. This type of erase operation is efficient from a user""s standpoint, as it tends to minimize cursor movements. However, prior art implementations of this function have involved extensive data manipulation which is not possible using the more limited processing resources of a pen-based computer system.
Therefore, it would be advantageous to have a method and apparatus for allowing a user to quickly mark an area of information on a computer system to be erased. Also, such a method and apparatus would need to make efficient use of the computer""s processing resources so it would be practical to implement on a pen-based computer system.
The present invention may be characterized as either a method or an apparatus. When characterized as a method, the present invention allows a user to draw a closed periphery around an amount of information on the display of a pen-based computer system. The periphery information is transmitted to the computer system by a digitizing tablet. When received by the computer system, the computer system divides the area enclosed by the periphery into a number of lines. The computer system then processes each of these lines and determines the information to erase in a given line.